As more fully pointed out by Allan Warner in a writing entitled "Tang Termination Of Insulated And Bare Conductors", published in Coil Winding International, Volume 2, Issue 2 of August, 1978, the details of which are herein incorporated by reference, tang termination relates to the joining of insulated or uninsulated low resistance wires to a simple and inexpensive terminal by fusing, typically with the aid of a resistance welder. Early on, in the manufacture of small electric motors, armatures were machine wound and the lead wires inserted into slots in the commutator. The commutator was then dipped into a solder bath which burned away the insulation on the wire and joined the wires to the commutator. Unfortunately, this method was suitable only for relatively low production requirements utilizing relatively low temperature insulation systems.
As demand increased and higher temperature insulation systems became available, the first fusing method was developed to connect insulated lead wires in the slots in the commutator without the use of the solder bath. As demand continued to increase, ways were sought to eliminate the need for placing the wires into the commutator slots. Winding machines were developed to place the wires around pins or hooks to which the wires were soldered.
Soldering was ultimately eliminated through the introduction of fusing of terminal tangs. The terminals employed are normally formed from strip copper or brass and usually will have a tin plating. The tang terminal may be a part of a commutator segment, a bobbin termination system, printed circuit termination system, wire terminal or the like. Normally, the tang terminals are used with insulated, solid wire and the insulation thereon is removed during the termination process. However, tang termination methods may also be utilized with stranded or uninsulated wires.
Conventionally, the tang is somewhat "U" or "J" shaped. The wire is placed under the tang which is then mechanically closed and fused. Usually, the tang is closed simultaneously with fusing, although in some instances, the tang may be closed first so that the wires will not move as the tang and its supporting structure are moved to a fusing station.
Care must be taken to assure that the wires are not crushed by the tang during the closing or fusing process. Conventionally, the parts are heated and pushed together until all air between them is eliminated and the high points of one part are pushed into the low points of the other and vice versa. A surface adhesion contact then holds the parts together.
This contact is not a true weld, but is rather, a compression joint and its strength is not particularly great. This factor, coupled with the potential for crushing the wire, are perhaps the two greatest sources of flawed winding terminations encountered with the process.
The present invention is directed to overcoming one or more of the above problems.